Long-term chemiluminescent signal is produced in the course of luminol peroxidation catalyzed by peroxidase isolated from leaves of African oil palm tree

Optimal conditions were found for the oxidation of luminol by hydrogen pero xide in the presence of peroxidase isolated from leaves of the African oil palm tree Elaeis guineensis (AOPTP). The pH range for maximal chemiluminesc ence intensity (8.3-8.6) is similar for AOPTP, horseradish, and Arthromyces ramosus peroxidases and slightly different from that for tobacco peroxidas e (9.3). Increasing the buffer concentration decreases the chemiluminescenc e intensity. As in the case of other anionic peroxidases, the catalytic eff iciency of AOPTP does not depend on the presence of enhancers (4-iodophenol and 4-hydroxycinnamic acid) in the reaction medium. The detectable limit o f AOPTP assayed by luminol peroxidation is 2.10(-12) M. The long-term chemi luminescence signal produced during AOPTP-dependent luminol peroxidation is a characteristic feature of the African oil palm enzyme. This feature in c ombination with its very high stability suggests that AOPTP will be a promi sing tool in analytical practice.